The vertical linear actuator mechanism of the present invention was conceived whereby to provide an extension assembly for raising and lowering a table top for use in an aircraft, train, or other passenger vehicles for the convenience of its occupants. Therefore, it is required that this table be adjusted to a comfortable level for use and be lowered to a position of non-use. A typical example of a floor rising cabin table is described in U.S. Pat. No. 5,947,416 wherein the table is connected to single pedestal and can be stowed under a floor surface when not required and then extended to a position of use to facilitate activities such as dining, paperwork, game playing, etc., as described therein. A major problem with such single pedestal tables is that the pedestals lack in strength, are not easily adjustable and not stable when raised to a position of use. Another disadvantage of such table assemblies is that they are normally operated by the electrical supply of the transport vehicle and when such supply is interrupted, such as during emergencies or other situation, the table cannot be lowered and could become a hazardous obstacle.
In U.S. Pat. No. 4,875,660 there is described a push actuator in the form of a telescopic tube which is sued as a lift actuator and which is constructed of two continuous bands of spring steel which are wound in a spiral and in a helix, respectively, with the turns of each band lying flat against each other in a retracted position of the tube. The turns of the respective bands are normal to one another. To extend the tube, the turns of the first band are spaced from each other and the turns of the second band are inserted between the space turns of the first band, so as to act as spacers for the latter turns. A mechanism causes extension and retraction of the tube. Such telescopic tubes have been developed for use in restricted spaces whereby to lift heavy loads and act as lifting jacks. A typical application of such telescopic tubes is to lift a floor section of a theatre scene wherein restricted space is provided under such floor section and therefore several of these lifting and retracting telescopic tubes are employed and positioned at different locations under the floor. These telescopic tubes have been developed for heavy duty work.